Background. B-CLL is one of the most common types of leukemia. Leukemic B cells are resistant to apoptosis, and microenvironment has large impact on their survival. In this microenvironment, an important role is played by monocyte derived macrophages and the substances they secrete (e. g. cytokines). Monocytes are the pregenitors of macrophages. According to genetic and immunophenotypic differences, monocytes are categorized into 3 subpopulations.
